fuel consumption advice please

[emcm0025]

Just managing to get my bayliner 2655 up and running proper after a long 2 months and time at 15mph new plugs and fuel filter upto speed again.

My question is that will a 4 blade prop cause more fuel burn than 3 blade?
The boat had 17inch pitch prop 3 blade which gave a wot of 28kts at 4700rpm and cruise at 18knts at 3800rpm

the 4 blade which just fitted today gave a wot of about 29 to 30knts at 4400 rpm and a cruise speed of about 20-22 knts at 3600-3800rpm and quicker on the plane, which im more happy at over all with the 4blade

What im trying to find out is with the 4blade down on revs will that be the same fuel burn over all as the 3 blade?, Would have at the higher revs?. And will the lower max revs do any harm to the engine long term? as they are down deom 4700 to 4400.

Sorry if this doesnt make much sence as its giving me one bad headache.

thanks to all who may read and help with these questions?

Ewan

 

[carlton]

As a Bayliner owner, I would strongly suggest you copy and paste your post here;

web page

It's the US based Bayliner owners club - I've had some terrific help from them. Give 'em a try - I'm sure you'll get the info you need.

 

[neale]

I agree, but you've got to learn the lingo first /forums/images/graemlins/grin.gif

Your question should be: Will I get better gas mileage.................?

 

[emcm0025]

Thanks for the link to that site just about to post on there.

All really wanting to know is will running lower max rpm damage the engine and is a 4 blade prop higher on the fuel burn over the same pitch and size as 3 blade?, to try and save me a pound or 2